I propose to examine some of the molecular events accompanying adrogen-induced rat ventral prostate cell growth and cell division. By manipulation of castration and replacement of hormone, prostate glands enriched in cells undergoing cell growth or cell division can be obtained. From these glands, parenchymal (acinar epithelial) cells and cell nuclei will be separated from stromal (connective tissue) cells and nuclei. Parenchymal cell nuclei will be separated into a chromatin fraction active in the synthesis of ribonucleic acids ("euchromatin") and less active "heterochromatin" (Experimental Cell Research 94, 1976, 1975). Information to be sought with nuclei or chromatin fractions from parenchymal cells undergoing growth or division includes: (1) additional properties of "eu" and "heterochromatin" and their interconversion as a function of steroid withdrawal or restitution; (2) the content, distribution and functional properties of nuclear acidic proteins, including androgen receptor/acceptor and cyclic nucleotide binding proteins present in these fractions, and (3) the properties and function of proteases associated with highly purified cell nuclei; especially their ability to degrade specific nuclear acidic proteins or basic histones during different stages of growth and development. The metabolism of androgens mediated by isolated parenchymal or stromal prostate cells will be examined, with the aim of relating differences in steroid metabolism to their physiologic states and to distinguish between contributions from the 2 classes of cells. Lastly, to provide additional evidence for the synthesis of nuclear proteins occurring independently of the cytoplasm, the tshl Chinese hamster ovary cell line with a temperature-sensitive defect in cytoplasmic protein synthesis will be used to study nuclear protein synthesis at the permissive and nonpermissive temperatures. Several aspects of this work, when established in the rat ventral prostate system will be repeated using normal and pathological prostate tissue provided by the G.U.